Compressor in air conditioning system



* M. PARCARO CGMPRESSOR IN AIR CONDITIONING SYSTEM Filed Jan. 26, 195;

Aug. 6, 1957 2,801,528

4 Sheeis-Sheet 1 INVENTOR Micfiael .Parcaro Aug. 6, 1957 M PARCAROCOMPRESSOR IN AIR CONDITIONING SYSTEM Filed Jan. 26, 1953 4 Sheets-Sheet2 INVENTQR Michael Parcaro Aug. 6, 1957 PARCARO 2,801,528

' COMPRESSOR IN AIR counrr onmc syswpu Filed Jan. 26, 1953 4Sheets-Sheet 3 INVENTOR Michael larcam BY M. PARcARo ,528 COMPRESSOR INAIR CONDITIONING SYSTEM Filed Jan. 26, 1953 Aug. 6, 1957 4 Sheets-Sheet4 1 5 102 I16 i I06 INVENTOR Michael Pal-Caro United States Patent flice2,801 ,528 Patented Aug. 6, 1957 COMPRESSOR IN AIR CONDITIONING SYSTEMMichael Parcaro, Arlington, N. J. i 1' Application January 26, 1953,Serial No. 333,143

14 Claims. (Cl. 62-115) This invention relates to refrigeration and airconditioning; and more in particular to a new system and new compressoror pump and flow-reversing valve arrangements, whereby the direction offluid flow is reversed automatically without auxiliary valves or thelike.

An object of this invention is to provide an improved refrigerationsystem whereby the refrigerant flow may be reversed. A further object isto provide a system wherein one element of the system is cooled duringone mode of operation, and wherein that element is heated by the simpleaction of a flow-reversing mechanism which forms an integral part of thecompressor. A further object is to provide an improved system of theabove character wherein successive refrigeration and defrostingoperations may be carried on in an eflicient and dependable manner.Another object is to provide a simplified and highly efficientair-cooling and heat-pump system. Another object is to provide arefrigeration system wherein a compressorunloading operation can becarried on in a dependable and efiicient manner. A still further objectis to provide an improved valve and compressor arrangement by which theabove may be accomplished. These and other objects will be in partobvious and in part pointed out below.

In the drawings:

Figure 1 is a somewhat schematic representation of a refrigerationsystem which is an illustrative embodiment of the invention;

Figure2 is a vertical section on the line 22 of Figure 1 with partsbroken away;

Figures 3, 4, 6 and 7 are sectional views on the respective lines 33,44, 6-6 and 77 of Figure 2;

Figure is a somewhat schematic sectional view of the valve mechanism;

Figure 8 is a sectional view on the line 8-8 of Figure 7;

Fig. 9 is a diagrammatic view of the compressor and valve assemblyarranged to unload volatile fluids from a tank car to a storage tank.

Referring now to Figure 1 of the drawings, the refrigeration system fora low temperature storage space is illustrated somewhat schematically.The air in the space is cooled by an evaporator 10 which has air coolingsurfaces below freezing upon which ice or frost accumulates and must beremoved by defrosting.

This refrigeration system comprises: a compressor and valve assembly 2,driven by an electric motor 4; a condenser-evaporator unit 6 enclosed ina water tank 7; a receiver 8; and, an evaporator-condenser unit 10. Thecompressor and valve assembly is connected to the evaporator-condenserunit 10 through a pipe 14. Unit 6 is connected to the receiver through aliquid line 16, which has a one-way valve 18 therein, through whichliquid refrigerant may flow to the receiver, but there can be no flow inthe reverse direction. Unit 6 is also connected to the receiver througha liquid line 20, having an expansion valve 22 therein. A similar liquidline 24 connects the receiver to the top of the evaporator-condenserunit 10, and has an expansion valve 26 therein. The top of unit 10 isalso connected to the receiver through a line 28, having a one-way valve30 therein, through which liquid refrigerant may flow from unit 10 tothe receiver, but there can be no flow in the reverse direction.

Line 28 also has a pan-heating coil 32 connected therein so that hotliquid flowing from the evaporator flows through this coil and heats thepan and condensate outlet. Assuming that motor 4 is operating thecompressor, (and the compressed refrigerant flows from the compressor tocondenser-evaporator unit 6, this unit. acts as a con denser with therefrigerant being cooled by water in tank 7. The condensed refrigerantflows from the bottom of unit 6 through the one-way valve 18 and line 16into the receiver. The liquid refrigerant then flows from the receiverthrough line 24, and expansion valve 26 to the evaporator-condenser unit10. Unit 10 acts as an evaporator and cools air which is blown over itby a fan 34 so as to cool the refrigerated space. Controls are providedto maintain the desired operation.

However, as indicated above, evaporator 10 is below freezing and frostaccumulates, thus making it desirable to defrost the unit. During thedefrosting operation, the compressed refrigerant flows through pipe 14to unit 10, which acts as a condenser so as to heat the evaporatorsurfaces. The refrigerant is condensed and flows through valve 30, coil32 and pipe 28 to the receiver. .The liquid refrigerant flows throughthe receiver through line 20 and expansion valve 22 to the bottom ofunit 6, which acts as an evaporator to extract heat from the water intank 7. The gaseous refrigerant returns to the compressor through pipe12. Thus, the surfaces of unit 10 are heated so as to melt the ice free,with the water flowing through tank 7 being the heat source. In flowingdownwardly the condensed hot refrigerant passes through the coil 32 soas to heat a pan beneath the evaporator into which the melted frostdrips. This insures that the melted frost will not refreeze, but willflow to a waste discharge, or trap.

When the system herein disclosed is used as outlined above, the reversalof flow is effected automaticallyby a reversing valve assembly 36, whichis part of the head of the compressor. This assembly includes thereversing valve portion 38 and the operating portion 40. The assembly 36is operated by supplying gas. under pressure to unit 40 through a line42 from a control unit 43. Assembly 36 is so constructed as to operatethesystem to cool the unit 10 when no pressure is applied through tube42, and the operation is reversed when pressure is applied. At the left,there is a high-pressure gauge 44, which is connected through a line 46to the outlet side of the compressor, and this line extends to thecontrol unit 43. At the right, there is suction gauge 48, which isconnected to the suction side of the compressor through a line 50, whichalso extends to unit 43. Unit 43 is connected to a controller 52 whichinitiates and controls the defrosting operations.

Figures 2 to 8 show the details of construction of the compressor andthe reversing valve assembly 36. Referring to Figure 2, the top of thecompressor cylinder block 54 is shown, there being two cylinders 56 and58 within which are two pistons 60 and 62. Closing the tops of thesecylinders is a valve plate 64, which carries for each cylinder a pair ofinlet valves 66 and a pair of outlet valves 68. The valve plate 64 iscovered by .a flow-reversing block 70 (see also Figure 3 and thesomewhat schematic showing of Figure 5), which has a top wall 72, with aperipheral downwardly extending wall portion 74 (Figure 2) and alongitudinal dividing wall 76 (Figure 3). The peripheral wall and thisdividing wall form two header chambers, there being an inlet headerchamber 78 into which valves 66 (Figure 2) open,

and an outlet header chamber 80 into which valves .68

open. Thus, the inlet and outlet valves 66 and 68 are positioned so thatthe inlet ports draw the gas from the inlet chamber 78 and the outletports discharge the compressed gas into the outlet chamber 80.

The reversing valve assembly is mounted in a cylindrical shell 82integral with the top wall 72. There are two valve stems (see Figure 8)84 and 86 slidably mounted in sleeves in a fixed plate 88 which isclamped at its periphery by stud bolts 90 and the flange of a cylindershell 92. Slidable in the cylinder shell 92 is a piston 94 to which theupper ends of valve stems 84 and 86 are rigidly attached. Valve stem 84carries a pair of valve elements 96 and 98 which are moved together bythe stem between the lower position shown with element 98 seated and anupper position wherein element 96 is seated. When element 98 is seated,the central chamber 100 is open to an upper chamber 102; and, whenelement 96 is seated, chamber 100 is open to a lower chamber 104. Valvestem 86 carries a similar pair of valve elements 106 and 108 which arereversely disposed so that element 106 is seated when the stem is downand element 108 is seated when the stem is up. There is a centralchamber 119 which is open to chamber 104 when element 106 is seated, andis open to chamber 102 when element 193 is seated. As represented inFigure 5, chambers 110 and 104) are connected respectively to the outletchamber 89 and the inlet chamber 78 by passageways 114 and 112 (see alsoFigures 6 and 7). Chambers 102 and 104 are connected respectivelythrough passageways 116 and 118 to the gas inlet and outlet ports orconnections 120 and 122 (see Figure 1) upon the sides of the compressorcylinder to which pipes 14 and 12 are connected.

Piston 94 is adapted to slide between the positions of Figures and 8 soas to move the valve elements between their two positions thus toreverse the flow of refrigerant in the system. In the embodiment ofFigure 1, the normal flow is as first described, and the flow isreversed to defrost the evaporator. During the defrosting operation thefrost starts to melt immediately and the operation is completed inminimum time. The reversal at the end of the defrosting operation isfollowed immediately by cooling of unit 10. Fan 34 is stopped during thedefrosting operation.

This same general refrigeration system, particularly with thiscombination compressor and reversing valve assembly is ideally suitedfor heat pump systems where cooling is produced in the summer andheating is produced in the winter. With such operation, the control isautomatic, and changes between cooling and heating are made inaccordance with the demands of the conditioned space. This assembly mayalso be used for 11nloading one or more cylinders of a multi-cylindercompressor. In such cases the reversal of the flow, i. e., intake anddischarge, of one cylinder or one pair of cylinders reduces the suctionand head pressures because there is a short-circuit of the refrigerant.Thus, for example, with one-half of the cylinders reversed, the entirecompressor is unloaded.

The compressor and reversing valve assembly is also ideally suited formulti-staging a multi-cylinder compressor system, or a system having twoor more compressors may be multi-staged. For example, a refrigerationsystem having two or more cylinders or pairs of cylinders may beoperated normally as a single stage system with all of the cylinders inparallel; and then, one or more of the cylinders may have their flowreversed automatically and the flow circuit changed to two-stageoperation. In this way, it is possible to provide an extremely lowtemperature, for example, to perform pre-cooling or freezing operationswith the multi-stage arrangement, while the single-stage operation isused to handle the normal load. This arrangement for single andmultistage operation may also be used in a heat-pump system to increasethe heat output range and the versatility. Thus, with a heat-pumpsystem, the single-stage operation will carry the heating load when thetemperature of the A heat source medium is relatively high; when thetemperature of this medium drops, the heat-pump system changes overautomatically to its multi-stage operation.

The compressor and reversing valve assembly herein disclosed is alsoideally suited for incorporation into a system for unloading volatilefluids such as propane. As illustrated in Fig. 9, such a system isprovided for unloading propane from railway tank cars 130, and fordelivering it to stationary storage tanks 132. During the initialunloading operation, the liquid propane flows through a liquid line 134directly from the bottom of the tank car to the stationary storage tank.The compressor and valve assembly 2 is then operated to withdraw propanegas from the top of the storage tank 132 and deliver it to the top ofthe railway car tank 130, and this permits rapid flow of the liquid sothat all of the liquid flows from the tank car. The diiference inpressures in the tops of the two tanks is sufficient to cause the liquidto flow even though the level in the storage tank is above that in thecar tank.

When the liquid has all passed from the car tank 130, the propane gasstarts to flow through the liquid line, and a relay 136 in this line isresponsive to the change in the medium which is flowing. This relay 136automatically closes a valve 138 in this line so as to stop the flowtherethrough. This relay also reverses the valves of the compressor andthe reversing valve assembly so as to withdraw the propane gas from thetank car and pump it into the storage tank. A piping and valvingarrangement is provided whereby this propane gas under pressure isdelivered to the body of liquid in the tank and bubbles upwardlytherethrough so that it is condensed. When the suction pressure, whichis the pressure in the car tank, is reduced to a predetermined value,the operation is discontinued automatically.

This same arrangement may be provided for transferring liquids or fluidsbetween various tanks, either stationary or mobile. With such operationthe compressor may be referred to as a pump because its primary purposemay be considered a pumping operation with there being a relativelysmall difference between the intake and discharge pressures. Theassembly is therefore referred to as a pump and reversing valveassembly.

In each of the embodiments herein disclosed, it is apparent that theunitary compressor or pump and reversing valve assembly produces anentirely new mode of operation. The heat exchange relationship betweenthe inlet and outlet streams insures proper and eflicient operation atall times. The results are uniform, and the reversing operations arecarried on without any objectionable efiects.

I claim:

1. In a refrigeration system, an evaporator which tends to accumulatefrost during a cooling operation, a condenser, and a unitary compressorand reversing valve assembly which normally delivers compressedrefrigerant to said condenser and withdraws refrigerant from saidevaporator, said assembly being adapted to reverse the refrigerant flowso as to deliver compressed refrigerant to said evaporator to melt thefrost free, and said unitary compressor and reversing valve assemblycomprising a compressor head having passages for the flow of refrigerantto and from the compressor and reversing valve means mounted in the headand cooperating with said passages therein.

2. A system as described in claim 1 wherein said cornpressor drawsrefrigerant in through an inlet chamber in the head and deliverscompressed refrigerant out through a discharge chamber in the head, afirst pipe means connecting said assembly to said evaporator, a secondpipe means connecting said assembly to said condenser, and in which saidreversing valve means and passages are in heat exchange relationshipwith the compressor and connect said chambers respectively to said firstand second pipe means and to reverse said connections.

3. The system as described in claim 2, which includes a reversing valvecomprising, a pair of parallel valve stems, two pairs of valve elementsmounted with one pair on each of said stems, a valve body having twocentral valve chambers associated respectively with said stems and eachhaving two discharge ports which are closed alternatively by saidelements.

4. In a refrigeration system, a compressor unit having a head, passagesin the compressor head terminating in inlet and outlet ports, and areversing valve assembly mounted in the head of said compressor andcooperating with said passages in said head for directing fluid throughthe passages in heat conducting relationship with said compressor.

5. A system as described in claim 4 wherein said reversing valveassembly includes an inlet chamber and an outlet chamber, and two doublevalve elements connected to control the flow.

6. A system as described in claim 5 which includes, anevaporator-condenser, a condenser-evaporator, and expansion controlmeans through which liquid refrigerant is supplied alternatively.

7. In a fluid pumping system of the character described, the combinationof, a pair of containers for a volatile fluid, and a unitary pump andreversing valve assembly connected between said containers and includinga pump having a head with fluid passages therein and a reversing valvein the head cooperating with said passages whereby the fluid may bepumped from one of said containers to the other and then said valve maybe operated to reverse the flow.

8. A system as described in claim 7 wherein said pump is of thereciprocating piston type which includes a cylinder block having fluidinlet and outlet passageways, and the head is a cylinder head assemblywithin which said reversing valve is enclosed.

9. A system as described in claim 8 which is a refrigeration systemincluding an evaporator wherein said reversing operation heats saidevaporator.

10. A system as described in claim 8 wherein one of said containers is atank car, and said unitary pump and reversing valve assembly is arrangedto supply gas from the other containers to the top of the tank car, andwherein said reversing operation withdraws and compresses gas from thetop of said tank car.

11. In a fluid pumping system of the character described, thecombination of, a pair of containers for a volatile fluid, and a unitarypump and reversing valve assembly connected between said containers andincluding a pump having a chamber in which fluid is pumped, a headprovided with intake and outlet passages to and from the pump chamberand a reversing valve in the head cooperating with said intake andoutlet passageways, said assembly having a block in which said pump iseni 8 closed, the intake and outlet passageways also extending throughsaid block whereby heat energy present in this block is readilytransferred to the fluid flowing through said passageways thus insuringcontinued operation of the pump when the valve is reversed.

12. In a fluid pumping system of the character described, the'combination of, a pair of containers for a volatile fluid, and a unitarypump and reversing valve assembly connected between said containers andincluding a pump having a head provided with intake and outlet passagesand a reversing valve with chambers in the head connected to the intakeand outlet passages, said pump including a block with a cylindertherein, said intake and outlet passageways being formed through aportion of said block whereby any fluid flowing in said passageways tosaid valve chambers will be heated before it reaches the valve and pumpthereby safeguarding operation.

13. In a refrigeration system wherein the direction of flow of therefrigerant can be reversed by a reversing valve, a refrigerant pumphaving a pumping chamber and a head enclosing a portion of the chamber,said head having passageways leading to and from the chamber, andreversing valve means in the head and cooperating with said passagewaysto and from the chamber, and said passageways having substantialportions positioned in heat exchange relation with said chamber wherebyany re- 'frigerant liquid flowing in said passageways to and from saidvalves is converted by the heat energy present in the body of said pumpto a gaseous phase before it can reach said valve and pump.

14. The system as in claim 13 wherein said pump has a block forming saidchamber and through which substantial portions of said passageways toand from said chamber are formed.

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